The invention relates to a tightening device for use with a cable bushing or leadthrough arrangement of the kind which comprises a rigid frame structure having arranged therein a plurality of packing pieces, of which at least one presents a throughpassing cable-accommodating hole and which are placed in rows in the frame structure so as to fill the space in the frame structure from one end thereof, and which tightening device comprises a pressure plate which is located between the other end of the frame structure and the row of packing pieces located nearest said other end, and further comprises a tightening element which is arranged between said other end of the frame structure and the pressure plate for urging the pressure plate against the rows of packing pieces.
Cable bushings or leadthrough arrangements of this kind are well known to the art and are used to lead cables through walls and like structures. The frame of the cable bushing arrangement is secured in an aperture in the wall and the cables are passed through holes presented by the packing pieces, whereafter the rows of packing pieces are pressed together in the frame structure, with the aid of a tightening device that comprises a pressure plate and a co-acting tightening element. This known tightening element normally has the form of a screw which is passed through the frame structure and one end of which presses against the pressure plate. The other end of the screw is thus located externally of the outer surface of the frame structure, and hence provisions must be made which will enable this end of the screw to be reached, so that the screw can be turned. To avoid this, cable bushing arrangements are known with which the frame structure is provided with an outwardly directed sleeve in which the tightening screw is screwed-in from within the frame structure. Although the screw of this arrangement can be manipulated from within the frame structure, it is necessary to form in the wall in which the cable bushing is to be fitted a recess for accommodating the outwardly projecting sleeve. Thus, both of these known cable bushing arrangements have the drawback that the frame, structure has projecting externally thereof parts which must be let into the wall in which the cable bushing is to be fitted.